摘要
在循环平稳过程理论的基础上,提出一种用于分析循环平稳声场的偏相干方法一循环偏相干方法。传统的偏相干方法以二阶统计量为基础,在用于分析循环平稳声场时,由于忽略了循环平稳声信号的特殊的非平稳特性,无法反映此类声场的某些特征。循环偏相干方法采用二阶循环统计量理论取代普通的二阶统计量,将之用于循环平稳声场的部分声场分离时可以得到部分声场的循环谱密度分布,可以在不同的循环频率上反映声场的不同特征,而这些特征在功率谱密度上则混在一起,无法清晰地反映出来。因此,与只能得到部分声场功率谱密度分布的传统偏相干方法相比,该方法可更清晰地了解循环平稳声场中各个声源的特性。数字仿真结果验证了该方法的有效性和可行性。
Based on the cyclostationary process theory, the cyclic partial coherence method is proposed to analyze sound field radiated from multiple cyclostationary sources. The second-order cyclic statistics is adopted by the proposed method instead of ordinary second-order statistics. Instead of the power spectral density (PSD) distribution, the cyclic spectral density (CSD) distribution of partial sound field radiated from each source respectively can be obtained when the proposed method is applied in the decomposition of partial sound field of cyclostationary sound field. Different characteristics of sound field can be extracted by the CSD distribution in different cyclic frequencies, which may be mixed up in the frequency domain of the PSD distribution obtained by the ordinary partial coher- ence method, and not be shown clearly. Consequently, the proposed method can extract information about the cyclostationary sound field more accurately than the partial coherence method can, which is validated by a simulation instance.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2005年第7期174-179,共6页
Journal of Mechanical Engineering
基金
国家自然科学基金资助项目(10474065)
关键词
偏相干分析
循环平稳
循环自相关函数
循环谱密度
部分声场分离
Partial coherence analysis Cyclostationary Cyclic autocorrelation function Cyclic spectrum density Decomposition of partial sound field
